Bad MAP sensor?

[bcjjones]

Car is running horribly. Sputters, bogs, and misses while under boost. Wont build more the 10psi most of the time. Afr gauge goes from lean, to rich, to lean. Car knocks out of no where. Sometimes I can build 23 psi, mostly though its under 10 and bog down real bad. I suspect its the map sensor.

Questions I have are, I recently cracked the plastic "housing" on the map sensor but didnt break any of the wires inside. Might be a stupid question but is that plastic housing just for looks really or does it need to be air tight?

Also I would rather just pick one up from an auto parts store, Oreilly's, or somewhere similar. I went and got one for a 1993 Chevy Silverado but i'm assuming I got the wrong one because it didn't work. Plugged in just fine but the car would'nt even run. Looked identical but maybe the wiring is different?

Any help on where to get one locally or which vehicle they come off of would be very helpful. I dont want to order one and it not be my problem.

Thanks in advance!

 

[4g63t]

Car is running horribly. Sputters, bogs, and misses while under boost. Wont build more the 10psi most of the time. Afr gauge goes from lean, to rich, to lean. Car knocks out of no where. Sometimes I can build 23 psi, mostly though its under 10 and bog down real bad. I suspect its the map sensor.

Questions I have are, I recently cracked the plastic "housing" on the map sensor but didnt break any of the wires inside. Might be a stupid question but is that plastic housing just for looks really or does it need to be air tight?

Also I would rather just pick one up from an auto parts store, Oreilly's, or somewhere similar. I went and got one for a 1993 Chevy Silverado but i'm assuming I got the wrong one because it didn't work. Plugged in just fine but the car would'nt even run. Looked identical but maybe the wiring is different?

Any help on where to get one locally or which vehicle they come off of would be very helpful. I dont want to order one and it not be my problem.

Thanks in advance!

What map sensor do you need ? Do you need a gm style 3 bar 2 bar 4 bar? or a AEM or what? Everyone has a different part number. If you know what you have it wont be hard to get another one. Are you still using Jackal Speed Density, Ostrich 2.0?

Please do yourself a favor and read this link it will help you understand how it works and what you need to check to see if your old one is bad.

GM MAP sensor identification information 1 bar 2 bar 3 bar

I have a few 3 bars at my house if you need one pm me.

 

[NHerron]

If you have a vacuum pump such as a MityVac, and a simple voltmeter, you can test MAP sensors all day long. Tons of articles online on how to perform the test.

 

[MY1GDSM]

Questions I have are, I recently cracked the plastic "housing" on the map sensor but didnt break any of the wires inside. Might be a stupid question but is that plastic housing just for looks really or does it need to be air tight?

Yes and no... . It's best to keep it sealed up all together. I've seen this happen a couple times on cars running High boost, The nipple on the Gm style house just has a sensor something like this inside. Rather easy to build really.

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(Just for reference not exact picture)

They can lose the seal and loss boost or draw in vacuum threw the housing.

Not that hard of a fix just take some epoxy and seal the sensor back to the housing and fill the rest of the housing to be safe. Pretty easy to test to just run some compressed (regulated air) to the sensor and see it it's holding presure. Or like wise with a vaccum pump. You could even take a log and see if things are lining up. If this is a issue now the logged boost isn't going to be matching what you are seeing on your boost gauge.

Or pick up another from someone on here

Also I would rather just pick one up from an auto parts store, Oreilly's, or somewhere similar. I went and got one for a 1993 Chevy Silverado but i'm assuming I got the wrong one because it didn't work. Plugged in just fine but the car would'nt even run. Looked identical but maybe the wiring is different?

The Only car that came with a a OEM 3 Bar map and would work just walking into the parts store is from a 1989 Pontiac Firebird with a V6 3.8L Turbo Charged (the 8th Vin Digit is 7) Other Maps sensors are not gonna work and will be smaller 2 bar 1 bar etc... .

While technically you can easily run any linear map sensor in ECMLink ~ See here for setting them up

These are the only pre-difined ones

AVCR 3 and 4-bar
GM 3 and 3.3-bar
AEM 3.5 and 5-bar
Apex'I EL series
Greddy 52mm and 60mm
Turbo XS sensors